This invention relates generally to door security devices and in particular to door security devices using a bracket member adapted to receive a chain.
Most of the door security devices of the prior art comprised rigid bars adapted to pass across the door and be received in a latch on either side.
One device utilized a rod bent at one end to act as the pin for the door hinge. The bar reached across to the other side of the door to engage a latch attached to the door jamb.
Other devices utilized bars hinged at one side to swing vertically and rest on a bracket in the opposite side of the door. The bar was adapted to telescope so that it would be adjustable for all sizes of doors.
Still other devices used heavy bar members having latch mechanisms of various kinds at the end for release at the bar member to open the door.
The novelty in many of these devices generally rested in the latching mechanism.
Chain devices have been used in which the chain is attached to a bracket on one side of the door and received in a hinged, spring loaded catch engaging the links of the chain on the opposite side of the door.
A latching device for a gate utilized a flat plate with a T-slot adapted to receive the link of a chain wrapped around a post.
Generally such devices of the prior art were expensive to manufacture and not necessarily adaptable to use on a hinged door.